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ELECTRICAL COMPARATORS AND ITS WORKING

Electrical Comparators are used as a means of  detecting and amplifying small movements of a work contacting elements.

An electrical comparator consists essentially of  a pick-up head or transducer for converting a displacement into a corresponding change in current and a meter or recorder connected in the circuit to indicate the electrical change, calibrated to show in terms of displacement. Generally, an amplifier is needed to provide the requisite sensitivity and to match the characteristics of different parts of  the circuit. Electrical comparators can be classified according to the electrical principle used in the pick-up head. Most of the comparators use either a differential transformer, an inductance bridge, a strain gauge or a capacitor as a means of detecting movement of the gauging element.

There are different types of  electrical comparators. One kind called an electrolimit gauge is used to check or measure the outside diameter of a  roll. The object to be checked is placed on the anvil on the base under the overhanging gauging spindle. Movement of the spindle for its deviation from a standard dimension unbalances an electric circuit. The displacement is magnified electrically and shown on the dial or meter. 

Electrical comparators offer a number of advantages over the mechanical type. They have little or no moving parts and, therefore, they can maintain their accuracy over long periods. Also sensitivity of these comparators can be adjusted at will to suit the type of measurement being done. In general , a higher magnification is possible with these comparators as compared to that of  mechanical comparators. Electrical comparators are available having magnification from 600 to 10000 to 1 according to the meter used.


Electrical comparators


Other Common Types of Comparators :

* Mechanical Comparators. 

* Optical comparators. 

* Pneumatic Comparators. 


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